The development of 3G wireless communication networks by standards, such as HSPDA (High Speed Packet Data Access), EUL (Enhanced Uplink) will allow for higher data rates on the downlink channel (from the base station to the mobile station) and on the uplink channel (from the mobile station to the base station) and further on towards LTE/SAE (Long-Term Evolution/System Architecture Evolution).
HSPDA will for example allow for peak data rates up to 10 Mbit/s, shorter connection and response times and a huge increase in sector throughput, while the EUL will increase uplink data rates in a later HSPDA release. LTE/SAE, in turn, will offer similar advantages.
Nonetheless, while these advantages will benefit end-users and the use of resource hungry mobile applications, the improvements are in conflict with other parameters important in such wireless communication networks, such as current consumption both in the mobile stations and the base stations, volume, and others.
One attempt of dealing with the increased power consumption is the introduction of power amplifiers adapted to have high efficiency at high output powers and power amplifiers with high efficiency at lower output powers as shown in FIG. 1.
Here, the amplifier circuit comprises one amplifier for high output power and one for lower output powers, i.e., around 15 dBm. Even though the current consumption through this arrangement is reduced with respect to only one power amplifier, there is still room for reducing the current consumption even more and particularly for saving battery power in diversity systems, be it in receiver or transmitter diversity systems, or both.
Aspects of the invention provide an alternative way of reducing the current consumption in a mobile station or an access point in a wireless communication network.